kmemdup_nul() is more efficient than kmemdup_nul() if the size is known exactly. The description of kstrndup() already suggested: Note: Use kmemdup_nul() instead if the size is known exactly. Signed-off-by: Xianting Tian <xianting_tian@xxxxxxx> --- fs/ext4/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 330957e..be37556 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4016,7 +4016,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } if (sbi->s_es->s_mount_opts[0]) { - char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts, + char *s_mount_opts = kmemdup_nul(sbi->s_es->s_mount_opts, sizeof(sbi->s_es->s_mount_opts), GFP_KERNEL); if (!s_mount_opts) -- 1.8.3.1